The invention relates to an air cushion vehicle comprising a main engine driving a fan device and a traction wheel device, whereby an air cushion for the support of the vehicle is produced by said fan device and propulsion of the vehicle is obtained by said traction wheel device.
The propulsion of an air cushion vehicle usually gives rise to problems. Normally, the propulsion device is an air propeller. However, the efficiency of an air propeller is poor, and, moreover, the propeller is subject to a rather strong erosion wear. If the air cushion vehicle moves on sandy ground, the propeller may be worn out in as little as 200 hours. The propulsion of an air cushion vehicle by towing or by means of traction wheel units is also known. However, the known traction wheel increase quite considerably the weight of the air cushion vehicle and, besides that, considerable problems are caused by the power transmission to the traction wheel units. Since an air cushion vehicle needs power both for the generation of the air cushion and for propulsion, it is most important that a suitable power distribution between these two devices is obtained. The power distribution should operate so that, when more power is needed for the air cushion, this is obtained simply by reducing the power transmitted to the traction wheel units and vice versa.